


Thicker than Water

by fallingintodivinity



Category: Fantastic Beasts and Where to Find Them (Movies)
Genre: And it ain't you Theseus, Incest Kink, M/M, Not a lot of plot here folks, Only one brother wears the trousers in this relationship, Plot What Plot/Porn Without Plot, Sibling Incest, Translation Available
Language: English
Status: Completed
Published: 2018-11-20
Updated: 2018-11-20
Packaged: 2019-08-26 10:39:53
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,640
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16680073
Author URL: https://archiveofourown.org/users/fallingintodivinity/pseuds/fallingintodivinity
Summary: Theseus Scamander loves his little brother. He really does. That doesn’t mean that Newt doesn’t also drive himout of his bloody mindsometimes.[or: Newt Scamander’s Guide to Obtaining Polyjuice Ingredients]





	Thicker than Water

**Author's Note:**

  * Translation into 中文 available: [【授翻】Thicker than Water](https://archiveofourown.org/works/16746019) by [white_lemon](https://archiveofourown.org/users/white_lemon/pseuds/white_lemon)
  * Translation into Русский available: [Кровь не водица](https://archiveofourown.org/works/17806421) by [minty_mix](https://archiveofourown.org/users/minty_mix/pseuds/minty_mix)



> Warning for **sibling incest** between two consenting adults.

 

“Bloody h–” Theseus grunts, all the breath knocked out of him as his back slams hard against the sturdy oak bookcase behind him. The books on the shelves rattle alarmingly but don’t fall. “ _Newt –_ ”

His little brother’s reply is lost against Theseus’s skin as Newt noses up the column of Theseus’s neck, then sinks his teeth into the spot just beneath his jaw. Theseus jerks, hissing at the sting as Newt worries at the sore, tender patch of skin then soothes it with his tongue, wet little laps that drags a low groan from Theseus’s throat and makes his cock jerk in his trousers.

Newt shifts to cover Theseus’s mouth with his, kissing him wet and hungry. He presses into Theseus with his entire body, one thigh between Theseus’s legs and his erection a hot, hard line against Theseus’s hip. Newt’s gripping both of Theseus’s arms hard, short nails digging into his skin, pinning him up against the bookcase with surprising strength.

Theseus somehow always manages to forget that his little brother, tall but so lean, hides more strength in that lithe body than most people would've guessed. And now, bookcase digging into his back and his little brother pressed closely all along his front, Newt’s tongue in his mouth and _oh sweet Merlin_ Newt’s hand sliding down the front of his trousers, long clever fingers wrapping around his cock, oh, he's being reminded of Newt’s strength in all the best possible ways.

When Newt pulls back to suck in a deep breath, lips pink and wet and swollen, Theseus makes a heroic effort to gather his scattered thoughts and shoves halfheartedly at Newt, because Theseus Scamander is not a damned pushover.

“Don't think,” he rasps, voice hoarse, then licks his lips and tries again. “Don't think I don't know what you're trying to do, little brother.”

Newt laughs softly, low and heated. “No idea what you mean, Thes,” he says, eyes glinting with amusement and affection, then he lowers his head to bite and suck at Theseus’s neck again, and bloody _hell_ if this goes on Theseus’s neck is going to be one huge purple bruise and he will have to fend off some _very_ awkward questions from his nosy Aurors come Monday morning.

Purely in self defence, Theseus grabs two handfuls of Newt’s coat and spins them around, slamming Newt against the bookcase Newt’d had him pressed up against. The shelves clatter dangerously and a thick book gets jostled out of the top shelf, falling to the floor beside Newt’s foot with a loud thump. Neither man pays the book any heed.

Theseus leans in to kiss Newt again, sucking hard on his lower lip until Newt’s gasping and moaning so prettily into his mouth, thrusting his cloth-covered erection against Theseus’s thigh. Newt withdraws the hand he had down Theseus’s trousers but before Theseus can draw breath to protest the loss, his little brother fumbles at Theseus’s belt, getting it open and pushing his trousers and underwear down to his knees, and, _god_. Theseus is so distracted by the feel of Newt’s palm around his cock, thumb sliding over the vein on the underside, that he puts up pretty much zero resistance when Newt wrestles him to the ground until he’s splayed on his back on the carpet. Newt proceeds to straddle his lap and leans down to kiss him hard and dirty, which is totally cheating, but Theseus can't help but open up for it anyway.

And everyone who knows them thinks that Newt’s the quiet, shy one. Merlin, if only they knew.

Theseus is torn between a fucked up kind of pride that he’s the only one who gets to see his gorgeous little brother like this – with kiss-bruised lips parted and wet, panting and flushed and rock-hard under Theseus’s hand – and indignation that Newt seems to think he can manhandle his big brother around with such impunity.

Theseus grabs a fistful of Newt’s shirt and drags him even closer, savoring the tiny whines and mewls Newt makes as they kiss. He toes off his shoes and kicks off his trousers and underwear, then releases his grip on his brother so he can push Newt’s teal blue peacoat off and unbutton his shirt, which Newt hastily shrugs off before kicking his own trousers and underwear off too.

Newt smiles down at him, bright and affectionate, and Theseus is suddenly dizzy with how bloody _lucky_ he is to have this – to have _Newt_. His brother’s smile slants into something darker, wicked and hot as he reaches over to snag his discarded peacoat and reaches into one of its pockets, and – _hallelujah_ – takes out a bottle of lube, and through the haze of overwhelming lust clouding his brain, Theseus gives himself a mental pat on the back for gifting Newt a coat with lots of pockets.

Coherent thought comes to a screeching halt when Newt pours lube over his long fingers and reaches around behind himself, a small frown of concentration on his face as he stretches himself open, and Theseus has to grip the base of his cock hard as he very nearly loses it at the sight of his little brother fingering himself open so he can take Theseus’s cock.

By the time Newt’s working himself onto Theseus, flushed and panting softly, small rolls of his hips as he takes Theseus deeper until he’s fully impaled on Theseus’s cock, Theseus is so strung out that he feels like he’s been waiting for _days_ to come, every nerve ending lightning-hot and fizzing just under his skin.

“ _Oh_ – oh, fuck, _Newt_ – feels so good, little brother,” he groans as Newt starts to move, riding him hard and fast the way they both like it. Newt’s fair skin is slick with sweat and Theseus’s fingers fit into the grooves of his narrow hips like they were made for each other, him and Newt, every single part of them slotting together into one perfect whole.

“Thes, Thes,” Newt pants, clutching at him as Theseus wraps a hand around Newt’s rosy cock, heavy and hot in his fist. “Oh, _Merlin_.” He leans down to kiss Theseus again, fingers clenching in Theseus’s hair and tugging hard as his hips pump in perfect time with Theseus’s thrusts.

When they break the kiss to suck in deep breaths of air, Newt whispers breathlessly against his lips, “love you so much, big brother,” and that’s all it takes for Theseus to tip over the edge of orgasm, shouting Newt’s name as he spurts deep into his little brother, one hand clutching at Newt’s hip hard enough to leave bruises. Three more pulls on Newt’s cock with his other hand and Newt’s painting his chest and stomach with come, moaning loudly as he shudders his release.

Newt sprawls sleepily over him after, one hand idly toying with Theseus’s curls. They both make a muffled sound as Theseus’s softening cock slips out of Newt, and Newt reluctantly clambers off Theseus, making noises about getting them cleaned up.

After Newt’s left the room, Theseus rubs thoughtfully at his head, wincing slightly. Newt had tugged on his hair pretty damned hard earlier; he’d _definitely_ pulled out a few strands of hair at least, and Theseus has a pretty good idea as to where those strands of hair are going. It’s not like he hadn’t seen the cauldron of half-completed Polyjuice potion in Newt’s suitcase yesterday _with his own damn eyes_.

Newt’s Polyjuice addiction is probably going to come back and bite Theseus in the arse at some point. Most likely at an extremely inconvenient moment. Maybe Newt is going to try to sneak into the Ministry to forge papers – _again_ – for some new and extremely illegal addition to that zoo he carries around in that suitcase of his.

Theseus sighs heavily. Does it make him a bad Auror if this _keeps happening_ and he doesn’t put a stop to it? Just, well. It would take a stronger man than him to resist Newt’s damned mouth. Sweet Merlin, that _mouth_. Theseus loses the next five minutes or so thinking about the myriad things he’d like to do (and has done) to Newt’s mouth.

A faint scrabbling sound somewhere north of his left ear has him turning his head sharply, instantly alert. A pint-size Niffler stares at him, one paw on Theseus’s crumpled clothes and the other paw on a stray galleon it’d clearly obtained from the pocket of his discarded trousers. Theseus sighs again.

“Go away,” he tells the tiny Niffler.

The creature scampers away and Theseus throws an arm over his face with a groan. He’s got to talk to Newt about this Polyjuice thing. There are only so many mysteriously-approved permits that he can turn a blind eye to, and Newt’s newly-acquired horde of baby Nifflers is slowly but surely taking over his entire flat.

The door creaks open. Theseus lowers his arm and cracks an eye open to see Newt smiling down at him, still beautifully naked and holding a wet washcloth in one hand.

He tries to muster up the requisite amount of energy to scowl at his little brother but can’t quite manage it after the spectacular and energy-draining orgasm he just had. “If you wanted to brew up more Polyjuice,” he says pointedly, “you could’ve just taken a couple of hairs out of my hairbrush, you know.”

Newt doesn’t even have the grace to look guilty, the little brat.

“But it’s more fun this way, isn’t it, Thes?” he says laughingly, and kneels on the floor so he can bend over to kiss Theseus again, sweet and adoring, and Theseus knows right then that he’s going to continue letting Newt do whatever he damn well wants, because his little brother has him well and truly wrapped around his little finger.

Bloody buggering _fuck_.

 

 

End.

 


End file.
